Internal combustion engine



E. SCHIMANEK 2,075,231 INTERNAL COMBUSTION ENGINE Filed Nov. 21, 1954ATTORNEY 3 Sheets-Sheet l March 1937- E. SCHIMANEK INTERNAL COMBUSTIONENGINE Filed Nov. 21, 1954 3 Sheets-Sheet 2 my. m.

R a .N N m w w 6 l .m A 990M331 3 I k5 34 2 7 t. 4 m I z a M C/ 1 83 WMV March 30, 1937. E. SCHIMANEK INTERNAL COMBUSTION ENGINE Filed Nov. 21,1954 3 Sheets-Sheet 3 my. a

I NVENTOR Fly. 77

ZrrzzZJdz'rzzazzek ATTO RN EY Patented Me 30, 1937 INTERNAL COMBUSTIONENGINE Emil Schimanek, Budapest, Hungary, assignor to firm Socit duCarburatcur Stratus,

France Paris,

Application November 21, 1934., Serial No. 754,066

In Austria June 18, 1934 11 Claims. -(Cl. 123-103) This inventionrelates to a method of and means for automatically regulating the fuelor mixture supply to the engine of a vehicle or the like during changesinthe operative conditions,

5 more particularly during the period, during which the engine, runningidle, is driven by the vehicle, when slowing down, travelling downhill,or the like, through the change in pressure occurring in the suctionpipe of the engine,

w The present invention makes use 'for the automatic regulation of thefuel supply during changes in the operative conditions, of the pressurewhich is produced by the dynamic eflect of a gas or air flow emergingfrom an enclosed space with approximately constant pressure (atmosphericor exhaust chamber pressure) through a nozzle or the like into a space,in which there is a partial vacuum, on a surface disposed in the path offlow, which vacuum corresponds to the vacuum in the suction pipe of theengine, which varies in accordance with the changing operativeconditions, a solution of the problem, which avoids the disadvantages ofthe known purely mechanical solutions (friction of parts moving againstand so on). V

. In the drawings in which various forms of the invention areillustrated more or less diagram matically Figure 1 is a diagrammaticview showing in section a suction pipe of an engine embodying one formof the present invention.

Figure 1a is a sectional view of a suction pipe and associated partsembodying another form of the invention.

Figure 2 is a vertical sectional view of the suction pipe showing thevalve arrangement.

Figure 3 is a sectional view of a suction pipe of an engine embodying afurther form of the invention.

Figure 4 is a vertical sectional view and Figure 5 is a cross sectionalview of .a suction pipe and associated parts embodying a still furtherform of the invention.

Figure 6 isa view similar to Fig. 4 but showing the valvein inoperativeposition.

Figure '7 is a vertical sectional view and Figure 8 is a cross sectionalview of a suction pipe and one another, influence of the wear on theeffect Figure ll'is a cross sectional view. ofa suction pipe andassociated parts and Figure 12 is a verand associated parts embodyinganother form of the invention.

Figure 14 is a diagrammatic view showing the pressure curves.

Figures 15, 16 and 17 are vertical sectional views of a suction pipe andassociated parts of an engine, each embodying a still different form ofthe invention.

As is well known, the dynamic pressure which a stream of air emergingfrom a pipe opening or the like exerts on a surface, plate or opening orthe like disposed perpendicularly to its direction of flow istheoretically equal to the diflerence in pressure due to the velocity ofthefiow. Figs. 1 to 3 of the accompanying drawings illustrate theserelations, showing in a purely diagrammatic mannerthe suction pipe of anengine in cross-section and in longitudinal section.

In Fig. 1 it is assumed that the pressure n prevailing in the space orcompartment I,is less than the atmospheric pressure p: prevailingoutside this space at the point 11'. Consequently the stream of airemerges from the opening 3 at such a velocity that the dynamic pressureexerted on the surface 4, which forms the orifice of a pipe 5, istheoretically equal to pa-m. Hence the re sultant pressure n acting onthe orifice surface 4 will be equal to the sum of the dynamic prese sureat this place, mm, and the static pressure min the space I, that ispe=m+mm=p=.

to the eddying and friction with the air in the space I, become less,the further the cross-section of flow, in which the orifice l issituated, is from the orifice 3. Thus the dynamic eflect on the surfaceI will be reduced if the distance e between the orifices S-and I isincreased. The eifect of the friction and eddying is all the greater,the lower thevelocity of the flow. The pressure in the orifice l thusdepends in reality on the magnitude of the pressure difference Dz-p1 andon the distance e between the orifices I and 4.

The utilimtion of these relationsfor regulating the fuel-supply isefiected in accordance with of the engine a lower degree of vacuum withrespect to the atmospheric pressure will be formed in the suction pipeand consequently in the space I as well, than at high speeds ofrevolution.. The

shape of the space I and the dimensions of the.

pipes Ill and 5 and the distance e are so selected that at apredetermined speed of revolution or at the vacuumcorresponding to ofrevolution the fiow will take place as shown in Fig. 3 .and at theorifice 4 there will be atmos 'pheric pressure. The distance e maybeadjusted while the engine is running by displacing the pipe I. Aregulation of the speed of revolutionor of the vacuum, at which thedynamic eifect will adJust the fuel supply, can also be eifected byenlarging or reducing the connecting opening 23 between thespace I andthe suction pipe I. In Fig. 3 thlscan be effected by displacing theslide i2 .by means of the screw it.

In the mode of regulation illustrated in Figs. 1 to 3 the transitionfrom the state in which the fuel is conveyed in accordance with idlerunning to the state in which the fuel sumly is interrupted is a quitegradual one, and at the speeds during this transitional period aninsufficient quantity of fuel reaches the engine, causing the latter torun in an irregular manner. In order to over-' come this, the regulationor the interruption of the fuel supply can be eifected according to theinvention in such a manner, that through the provision of an auxiliaryregulating device, the dynamic effect can become fully operative orop-'- erative at all with a jerk at certain pressure the like.

This can be brought about in a very simple manner, as Fig. la shows, byshutting off the outer opening of the inlet pipe I. by means of a valve20, or the like. The valve 20 is connected to a diaphragm I!" which isunder the influence of the vacuum prevailing in the suction pipe I andpropagated through the small pipe 2!. Only when the excessive vacuumcauses the valve 20 to open will air flow through the openings Handthrough the pipe it into the space or compartment'I and the dynamiceffect become operative on the orifice .4 of the pipe 5 and interruptthe fuel supply until the vacuum in the suction 50 pipe has againreached the normal value corresponding to the idle running state.

The constructional examples according to the invention, illustrated inFigs. 4 to 10 have the advantage that no valves or the like requiring 65eifective sealing are used, so that anydisturbances in the operation,which might occur owing to such a valve not being tight, are avoided.

In the constructional example illustrated in Figs. 4, to 6 a movablescreen or plate I4 is inter- 7 posed between the orifices 2 and l. whichis capable of being rocked by an arm It about a pivot pin 2| and isforced upwards by a spring 22.

' When in its top position (Fig. 4) this screen covers the orifice 4with respect to the orifice I,

7 thus deflecting in the direction of the arrows 26 pressure throughopenings ll.

the flow of air and the fuel (or mixture) flowing out of the pipe I. Inthis position, therefore, the dynamic eflectof the inflowing air isdestroyed. The lower surface of a diaphragm I5 is acted on by the vacuumprevailing in the space. 24, while its upper surface is acted on by theatmospheric The diaphragm is further acted on upwardly by the force of aspring I! which is adjustable by the spring plate 18 on the bar l8. Bythe stop 20 the arm it of the screen it is swung in accordance with the-motion' of the diaphragm. As long as the vacuum in the suction pipe Iand consequently the vacuum in the space 24 does not exceed a definitevalue, the screen will be in the position shown in Fig. 4 and preventthe action of the dynamic effect on the orifice 4. when, however,the'vacuum in the space 24 exceeds a certain value, the diaphragm willbe bent'downwards in opposition to the spring pressure and the stop 20will force the arm- Ii and the screen I downwardsinto the position shownin Fig. 5 in dot and dash lines and inFig, 6 in full lines. The dynamiceilect of the stream of air on the orifice 4 will thus become fullyeffective and the entrance of fuel through the pipe I will be definitelycut oil. v

In order to assist the change over ofthe screen It from one positioninto the other and to cause it to take place as suddenly as possible,

I along the blade surface of the screen in the direction of the arrow26' and thereby exerts a force P1 on the blade, which assists in holdingthe blade in its upper position. The fuel (or the over rich idle runningmixture) fiows in in the direcv tion of the arrow 26 and exerts on' theblade a horizontal force which has no component in the direction .ofdisplacement of the screen H. On the screen. It being depressed by thediaphragm owing to the excessive vacuum in the space 24 (Figs. '1 and8), the edge 21 of the screen comes in front of the orifice l of thepipe I! and less and less air will flow over the blade the furtherdownwards the screen is moved, so that the force with which the screenis pressed upwardsbecomes smaller and smaller until itbecomes zero atthe position indicated by daslr and dot lines. Hence the change over,after it has'once been initiated, will take place suddenly, owing toforce P1 which is reduced to zero-by the change over.

When the screen is in the bottom position shown in dot and dash lines inFigs. 7 and 8, it will not hinder the fiow of air at all in exerting thedynamic effect on the orifice 4.

On the vacuum decreasing again and the diaphragm consequently retumlngto its-upper position, the screen I4 is forced out of its bottomposition, by the spring 22 upwards, its upward motion into the toppositiorrbeing suddenly accelerated by the force P1, as soon as the edge21 comes in front of the orifice 3, as this force will now rapidlyincrease from zero.

According to the invention the sudden change over of the screen can befurther assisted through the vacuum in the space I being suddenlychanged at the moment in which the screen is displaced by the diaphragm.i

In Figs. 9 and 10 such a constructional example 40 31 in the bottom ofthe cylinder 4|, the size of 3 gas in the opening. This velocity,however, oc-

is shown. The rod 19 which is connected to the with respect to thedirection of flowing is equal to diaphragm I5 is provided with a valve29, which v 3 increases or decreases the size of the opening 3- 23' andconsequently the connecting opening 23v g 5 between the space I and thesuction pipe 'I. Since the valve 29 is never entirely closed, it is notrequired to provide a tight closure.

The sudden change over of the screen can also When the pressure 101 in:a space or compartbeefiected by the diaphragm I5 which is influment I(Fig. 13), into which air flows out of a 10 enced by the vacuum beingused only as an interspace II in which the pressure 122 prevails, dropsmediary member, the deformation of this diabelow half the pressure p2(actually below 0.53m) phragm influencing any force exerting means, forthen, if no Laval nozzle is being used, the presinstance in theconstructional example shown in sure at the orifice 3 of .the inflowpipe III will Figs. 11 and 12 the vacuum formed in the space have theconstant value" 0.53m andthe outflow 15 or compartment I beingchangedand in consequence of this change of pressure thecorresponding'sudden displacement of a regulating member being efiectedby the constant (atmospheric) pressure prevailing in the space orcompartment I". In Figsll and 12' the diaphragm i5 is provided with anopening 23" which coacts with the cone valve 36 which is disposed in thebottom of a cyl r which is Pr d W ape u s as that shown diagrammaticallyin.Fig. 13 air 35. On the diaphragm being bent downwards flows throughthe pipe l0 out of the space 11 into 25 throu h a se in e v uu in thespa a. the space I, while through the pipe 5' no flow takes the P a ebetween the 1 9 3" and the place (as the' space or compartment IIIconnected 00116 6. be increased, whereby in the Space to it is shutoff), the'pressure in the space 111 is in the cy M e vacuum is increasede determined by two additive pressures: 1st through piston 38 Which isforced pw d y the Spring the static pressure in in the space I and 2nd34 is consequently suddently displaced into its through the dynamicpressure in of the flow of bottom position shown in Fig. 11 through thei atmospheric pressur prevailing in the Sp It follows from what wasstated at the comwhich acts on it from above. In this position themencement of th specification and in t Previair entering t ug the pWill, flowing vous paragraph that, on the vacuum in the space 35 throughthe passage 3! in the piston 38, exert I increasing (that is to say onthe pressure 121 the dynamic effect on the orifice! of the pipe 5.dropping), the pressure in the space III (pa) will When, however, owingto the diminution in the follow the course shown in Fig. 14: Owing tothe vacuum in the space 23a, the diaphragm libends friction and theeddying in the space I the vacuupwards until it comes in contact withthe stop um at the orifice 3 and therefore in the space III as wellwill, with a vacuum in the space I or in the P s we n the opening 23" ndt e the suction pipe increasing from zero, first of all cone 36 will bedecreased and the vacuum in the increase a-little, but'then drop againand at a Sp Will consequently e150 p, S0 at the definite pressure 121become zero again. This zero piston 38 is suddenly displaced by thepressure of value of the vacuum, which corresponds to a the spring 34into the top position, in which the pressure ps =pi+pi', will remainunchanged, un-

pipe orifice 3 is connected with the hole 32 and the til the pressure min the space I drops below the orifice I with the hole 32' in the wallof the pisvalue. 0.53m. From this point onwards the dyton 38 and thescreen 33 of the piston prevents namicpressure p1 remains constant andconsethe dynamic effect becoming operative. quently the pressure p4 atthe orifice 4 or m in For the sudden interruption and-'re-establishthespace III become smaller and smaller as in dement ofthe fuel supply theinfluence of the crit-- creases, that is with an increasing vacuum inthe ical outflow velocity on the dynamic effect can suction pipe. Inother words, the vacuum at the also be utilized, as is illustrated inFigs. 13 to 17.

gravity.

pendently of the pressure in the space I, always be equal to thevelocity of sound. Hence, the dynamic pressure exerted on a surface,plate or opening 'or the like, disposed in the path of the flow of air,will always remain constant, as long as the pressure in the space Iamounts to less where v=velocity of flow of the gas, 'y=the specificweight of the gas and g=the constant of velocity of the air from thisorifice will, indethan 0.53m. Thus, when in an arrangement such orificel and in the space III will become greater.

It is aphysical law that if a gas flows out of a, and greater the riseof the vacuum being a rapid space with a higher pressure (91) through anone. When the space I is connected to the sucopening into a space with-alower pressure (1) then the velocity wherewith the gas flows throughsaid opening is given by the formula where g=".81 m./sec.' (=theacceleration of gravity), p=pipr the 'pressure-difierence between thetwo spaces, and 'y thesspeciflc weight of the which the vacuum isgreater than half an atmosphere, the vacuum produced in the space I canbe given different values by altering the crosssection of the connectingpassage 23. Hence in the space I the absolute pressure 0.53;): will, on

reached sooner or later, according to whether the connectingcross-section 23 is greater or smaller. If therefore, as-shown in Fig.14, the

curs only so long until the pressure 92 becomes vacuum in the space IIIbe represented as a func- =0'.528 m. In this case the ve ocity ofoutflow of y then we obtain th res ure 0 r the gas is equal to thevelocit of sound. 8 p s m 0 m or m and so on, according to the sizeofthe connecting thereulfoni Smaller than 0 cross-section 23.- The vacuumin the suction pipe, 1 the Velwlty' of outflow (195 not grow any atwhich the snddenchange of the pressure .1): longer, but remainsconstantly the same asv by occurs, can t b t This sudden'im pz=f0.528111.

Itis also a well known principle that the stowfor regulating the fuelsupply through the space pressure on a plane perpendicularly arranged111 being shutoff by a diaphragm, piston or the tion pipe of the engineor to some other space in crease in thevacuum in the space 111 isutilized tion of the vacuum prevailing in the suction pipe,

the vacuum in the suction pipe increasing, be.

like. The sudden increase in vacuum bends the diaphragm or displaces thepiston or the like,

whereby the fuel supply can be influenced. Making use of theserelations, constructional 6 examples are shown in Figs. 15 to 17, inwhich for example a more complicated arrangement, viz. a carburettorarrangement is used, which has a main nozzle 54 for the operation and aseparate nozzle 55 for idle running. The float casing 56 with 1d thefloat 51 and the venting opening 58 is constructed in the'usual manner.

InFig. 15 the space in is shut off by a dia- 'phragm I "which, on thevacuum increasing, closes a valve 50, and thereby cuts off the supply ofthe fuel flowing through the upright pipe 5i. Hence no fuel can flowinto the suction pipe "I through the idle running pipe 52. I

In Fig. 16 the vacuum which suddenly rises in the space In closes bymeans of the diaphragm 2 t5 the valve 59, through which the atmosphericair pressure is transmitted through the opening 5| into the upper spaceof the float casing 56, and

at the same time opens the valve 60, so that simultaneously the floatcasing is shut ofl fronrthe atmospheric pressure and the vacuumprevailing in the space 6| is transmitted into the float chamber 58.Owing to this pressure equalization, the

conveyance through the idle running nozzle 55 ceases, until the vacuumin the space III has again suddenlydropped to zero or approximately tozero and the diaphragm ll again chang over the valves 58, 80.

In Fig. 17 a constructional example is shown,

in which the dynamic efiect is' doubly utilized: flrstly, as in-theprevious examples (Figs. 15 and 16) at the orifice 4 in the-flow of aircoming from the orifice 3, whereby the suddenly increasing vacuum p3illustrated in Fig. 14 is causedto act on the diaphragm l5; secondly,-at the nozzle 56 through the opening of the valve 82, the air nowingthrough the passage 61 cutting on, owing to its dynamic eifectj the fuelsupply through the nozzle 55, as soon as the valve 62 is opened. Thevacuum in the suction pipe, at which the doubly utilized dynamic efl'ectbecomes eifective, can be regulated as desired by altering theconnecting cross-sectionZLwhich may be carried out in'any suitablemanner. I

An adjustment of the device shown in Figs. 18 0. and I1 may be madesimilar to that shown in Fig. 3. Thus the connecting opening canbeenlarged or reduced by means of the slide it.

What I claim is:

1. An apparatus for automatically regulating 5 the fuel supply to aninternal combustion engine having a suction pipe connected with a fuelsupply system comprising means for cutting oi! the fuel supply throughthe automatic application to the fuel supply system of a substantiallyconstant pressure when theengine speedmaintains a suction in said pipeto create a pressure therein less than said substantially constantpressure.

2. An apparatus for automatically regulating the fuel pply to aninternal combustion engine comprising a suction pipe, a throttle valvein said -65 suction pipe, means providing a source ofsubstantiallyconstant pressure to said pipe. and.

means connectedto the flow path of the fuel supply and communicatingsaid pipe whereby the gas supply to the engine is automaticallyinterrupted by means of the source of substantially constant pressurewhen the throttle valve is closed and a suction remains in said pipe. V

3. In an apparatus for regulating the fuel supply for an internalcombustion engine, a suction m sg g tion with latter pipe,"a' diaphragmorming one wallof said-latter'compartment, a nomle in pipe, a throttlevalve in said suction pipe, a com- 7 partment in communication with saidsuction pipe at a point behind the valve, a pipe having one endterminating in said compartment and its other end communicating with theatmosphere I and a fuel supply pipe having one end terminating in saidcompartment, one of said pipes being movable .relatfve to theotherforadiusting the dis tance therebetween.

4. An apparatus as described in claim 3 charl0 -acterized by having amovable member in the line of communication between the suction pipe andcompartment for adjusting the cross sectional area of said line ofcommunication. I

5. An apparatus as described in claim 3 char acterized by having a valvein the air supply pipe leading to the compartment and a diaphragm foractuating said valve, said diaphragm being under the influence of avacuum on one side and of atmospheric pressure on the other side.

' 6. In apparatus of the kind described for in'ternal combustionengines, the combination with the suction pipe and a throttle valve inthe pipe, of a compartment having a passage in communication with thesuction pipe at a point behind-the valve, an air supply pipe having oneof its ends terminating in said compartment and its other endcommunicating with the atmosphere,1a pipe having one of its endsterminating in the. com- 'partment,.another compartment in co unica- 30the fuel supply line, and a valvein the fuel supply linecontrolling saidnome, said diaphragm being operatively connected to said latter valvefor actuating the same.

7. In apparatus of-the kind described for'internal combustion engines,the combination with the suction pipe and a throttle valve therein, of acompartment having a e communicating with said suction pipe behind saidvalve, an air supply pipe having one and terminating in the compartmentand its other end communicatingwith the atmosphere, a pipe having oneend terminating in the compartment. another compartment in communicationwith said latter pipe, a diaphragm forming one wall of'saidlattercompartment, a fuel casing in normal communication with theatmosphere, a pipe'incommlmicationwith said casing for conveying fuelfor idle run ning, a nozzle in said latter pipe, and mechanism forcutting oi! direct communication-between the I casing and atmosphere andestablishing communication between said casing and the suction pipewhereby the pressure in the casing and second named'fuel pipe isequalised, said "including a pair of'valves adapted to beoperatedinunison lathe-diaphragm, one ofsa'idvalves beinginthe line ofcommunication be-; tweensaidcasingandtheatmosphereandthe other in theline of communication between the casingandthesecondnamedfuelpipaanda,i'ioat'in the fuel casing adapted tobe influenced by eitherof saidlatter valves for controlling the fuel supply for idle.

8. Inapparatus of the kind described for internal combustion engines,the combination withthe suction pipeand a throttle valve therein, of 'acompartment communicating with said suction pipe behind said valve. onair supp y'pipe having incommlmicationwithsaldplpaadhphrsmn.

forming one wall of said second named compartment and mechanism forconveying fuel for idle running including a pipe, a nozzle therein, anda valve in an air supply pipe conveying air to said nozzle, said lattervalve being operatively connected to the diaphragm whereby atmosphericair is admitted to the nozzle for creating a dynamic efiect thereon toinfluence the fuel supply.

9. Apparatus of the lzind described in claim 3 characterized by aregulating device which subjects the fuel supply to the action or a backpressure when a certain predetermined vacuum is exceeded and whichpermits withdrawal of said. action upon the return to normal runningcondition.

10. In an apparatus for regulating the fuel supply for an internalcombustion engine, a suction pipe, a throttle valve in said suctionpipe, a

compartment in communication with said suction pipe at a point behindthe valve, a pipe having one end terminating in said compartment and itsother end communicating with the atmosphere and a fuel supply pipehaving one end terminating in said compartment.

11. In' a device for automatically controlling the fuel supply for aninternal combustion engine, a suction pipe having a throttle valvetherein, a compartment communicating with said suction pipe behind saidvalve, a pipe leading from the atmosphere into said compartment, and apipe means opposite and spaced from said atmospheric pipe in saidcompartment to vary in conjunction with said atmospheric pipe the fuelsupply upon variations of pressure in said suction pipe.

EMIL SCHIMANEK.

